added TEXTALIGN command to change the default text alignment

[rrdtool.git] / doc / rrdgraph_rpn.pod

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index 5000d7a..cf62c08 100644 (file)
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -127,6 +127,10 @@ B<DEG2RAD, RAD2DEG>
 
 Convert angle in degrees to radians, or radians to degrees.
 
+B<ABS>
+
+Take the absolute value.
+
 =item Set Operations
 
 B<SORT, REV>
@@ -139,7 +143,14 @@ Example: C<CDEF:x=v1,v2,v3,v4,v5,v6,6,SORT,POP,5,REV,POP,+,+,+,4,/> will
 compute the average of the values v1 to v6 after removing the smallest and
 largest.
 
-B<TREND>
+B<AVG>
+
+Pop one element (I<count>) from the stack. Now pop I<count> elements and build the
+average, ignoring all UNKNOWN values in the process.
+
+Example: C<CDEF:x=a,b,c,d,4,AVG>
+
+B<TREND, TRENDNAN>
 
 Create a "sliding window" average of another data series.
 
@@ -163,6 +174,12 @@ average is essentially computed as shown here:
      Value at sample (t1) will be the average between (t1-delay) and (t1)
      Value at sample (t2) will be the average between (t2-delay) and (t2)
 
+TRENDNAN is - in contrast to TREND - NAN-safe. If you use TREND and one 
+source value is NAN the complete sliding window is affected. The TRENDNAN 
+operation ignores all NAN-values in a sliding window and computes the 
+average of the remaining values.
+
+
 =item Special values
 
 B<UNKN>